Electrode assembly apparatus



y 1951 A. D. AIRD ETAL 2,985,947

' ELECTRODE ASSEMBLY APPARATUS Filed Jan. 23, 1958 2 Sheets-Sheet 1 FIG.|. FIG.4. i 3 I I I 2 FlG.2.

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I C7 C1 INVENTORSI ALANSON D. AIRD, WILLIAM F. CRANE,

May 30, 1961 A. D. AIRD ET AL ELECTRODE ASSEMBLY APPARATUS 2 Sheets-Sheet 2 Filed Jan. 23, 1958 INVENTORS I ALANSON D. AIRD, WILLIAM F. CRANE,

. T ATTORNE Unite States Patent Ofiflce 2,985,947 Patented May 30, 1961 2,985,947 ELECTRODE ASSEMBLY APPARATUS Alanson D. Aird, Scotia, N.Y., and William F. Crane, San Francisco, Califi, assignors to General Electric Company, a corporation of New York Filed Jan. 23, 1958, Ser. No. 710,819

3 Claims. (Cl. 29-2519) This invention relates to the manufacture of electron discharge devices and more particularly to apparatus for automatically assembling electrodes of such devices of the type, such as receiving tubes, wherein the electrodes are of small size, light weight, and delicate nature.

Electrodes of electron discharge devices, such as receiving tubes, are generally of longitudinal hollow cylinder-like form, such as for example cathodes comprising tubes of square, circular or elliptical cross section, grids comprising helically coiled wire of cylindrical or cylinder-like outline, and anodes of cylinder-like or particylinder-like form. Generally such electrodes are assembled and supported, usually in coaxial spaced relation, between transverse insulative plates, such as thin plates of mica. The mica plates are formed with precisely located apertures through which extend the ends of the electrodes or electrode frame members as the case may be, and thus the micas afford firm support to the electrode as well as permanently securing the electrodes in precisely-spaced relationship for proper electrical operation of the discharge device with its intended electrical characteristics.

The desirability of eliminating costly hand operations in the assembly of such mass-produced articles as receiving tubes has been recognized for some time. Reliable automatic apparatus for rapidly assembling the several fragile parts of an electron discharge device, such as a receiving tube, has long been sought. However, the small size and delicacy of the parts involved, the need for adherence to relatively close tolerances in positioning and spacing of parts during assembly, and the resulting undesirability of using apparatus involving violent motion or large forces inherently makes many conventional types of apparatus unsuitable.

Accordingly, a principal object of the present invention is to provide apparatus for automatically assembling electrodes of electron discharge devices such as receiving tubes which will handle the parts gently yet at a rapid rate suitable for automated production and which will insure proper location of the assembled parts with the precision required, for example, in the receiving tubes.

Another object is to provide such assembly apparatus which has relatively few moving parts and few parts with close tolerances, which is of small size suitable for convenient installation in an assembly line, and which will operate reliably for long periods as required in continuous automated production without requiring repair or adjustment.

Briefly, according to one aspect of the present invention, an electrode to be assembled is supplied through a channel in a guide member to a position near its correct permanent position relative to an insulative support plate. A portion of the guide member is movable and is used to snugly and precisely position the electrode in another channel of another guide member in axial registry with the insulative support plate. The latter guide member is axially movable to enable the electrode to be brought into juxtaposition with the insulative support plate. A ram movable axially in the channel of said other guide 2 member is used to secure the electrode in the insulative support. Said other guide member is then axially retracted from contact with the electrode while the ramis still in engagement therewith. The ram is finally retracted, thereby completing the assembly of the electrode in the insulative plate.

In the drawing:

Figure 1 is a perspective view of a mica support plate with a cathode mounted thereon;

Figure 2 is a sectional view of the mica support plate and cathode mounted on a support block preparatory to mounting a grid thereon in accordance with the present invention;

Figure 3 is a perspective view of the mica support plate and cathode after assembly of a grid thereon in accordance with the present invention;

Figure 4 is an elevation view of an electrode assembly apparatus constructed in accordance with the present invention;

Figure 5 is a fragmentary view of Figure 4 showing the disposition of a grid assembly in a first guide or feed channel of the apparatus of the present invention;

Figure 6 is a fragmentary view of Figure 4 after an erector in accordance with the present invention has positioned the grid assembly in a ram channel of a second guide member and the latter has moved the grid into position over the mica support plate;

Figure 7 is a sectional view of Figure 6 taken along section line 7-7;

Figure 8 is a fragmentary view of Figure 4 showing grid support plate bythe seating of the grid assembly in means of a ram or plunger; and

Figure 9 is a fragmentary view of Figure 4 showing the ram channel assembly retracted with the ram in place at the completion of the grid assembly operation in accordance with the present invention.

Referring to the drawings, the present invention is illustrated in connection with the assembly of a control grid of an electron discharge device of the receiving tube type, onto a support plate of mica or other insulative material apertured to receive the grid, and in coaxial surrounding pleted tube, and the free end of the tab is bent inwardly 1 toward the cathode axis to avoid obstructing other electrodes to be assembled to the mica.

As shown in Figure 2, the cathode with which the grid is to be assembled may conveniently be supported on a fixture or mount block 4 with the cathode 3 held in an upright position by a pin 5 carried by the mount block and the mica 1 laying flat on a horizontal shelf at the base of the pin, the mica being properly oriented relative to the mount block or fixture 4 by suitable holders (not shown) on the fixture 4.

Figure 3 shows the mica 1 and cathode 2 after assembly, by the apparatus of the present invention, of the grid 6. The grid includes a cylinder-like helix 7 of fine wire wound on and fastened by notching or peening, for example, to a pair of longitudinal side rods 8 forming a supporting frame. The lower ends of the side rods serve as feet which are inserted snugly through matching apertures in the mica 1, and thus the mica holds the grid firmly as well as spaces it exactly relative to the cathode 2.

Turning now to Figure 4, the electrode assembly apparatus of the present invention includes a frame 10 at the base of the front of which is an apron or ramp 11 adapted to receive the fixture 4 and onto which the fixture may be conveniently placed either manually or by suitable placement apparatus. Adjacent the ramp is apair of vertical mutually perpendicular reference surfaces 12 and 13 on the frame against which the fixture 4 is accurately positioned, for accurate location of the mica carried by the fixture 4 relative to the frame 10. Situated above the supporting ramp 11 are the grid placement assembly 14, the ram or plunger assembly 15, and the grid feed assembly 16. The grid placement assembly 14 is movable with respect to the mounting block 4 by means of air cylinder 17 which is attached to the frame 10 and includes a piston which is connected to the assembly 14, enabling the assembly to move with respect to the frame in an axial direction with respect to the cathode 2. A suitable guide or guides 18 may be provided to insure accurate movement of the assembly.

The grid placement assembly 14 includes a first channel 19 axially aligned with respect to the cathode 2 and includes the ram or plunger 20 slidably movable therein by means of air cylinder 21 which is fixed to the frame 10. Accordingly, it is seen that the grid placement assembly 14 and the ram 20 are independently movable with respect to the frame 10. The grid placement assem bly also includes a feed channel 25 for supplying grid assemblies to the main placement channel 19. The feed channel 25 is obliquely situated with respect to the main channel 19 and opens into it. Each of the channels 19 and 25 include guide portions for assuring accurate azimuthal alignment of the cylindrical grids with respect to the mounting plate 1. For example, the channels may be rectangular in cross section and the grids may be elliptical in cross section. Accordingly, the corner portions serve as azimuthal aligning guides for the grids. The grid placement assembly 14 also includes longitudinal erecting member 26 forming a part of the base of channel 25 when it is situated in one position and forming a portion of the wall of the main channel 19 when situated in the other position. Air cylinder 27 is arranged to move the erecting member 26 from one position to the other as desired. In the upright position, the erecting member 26 securely holds the grid 6 in position for erection in the mica 1 as will be more clearly explained in connection with the operation of the machine.

Fastened to the upper top portion of the frame is a grid feed assembly 16 having a chute or channel 30 positioned in registry with the oblique channel 25. At an end remote from the grid placement end of the channel, a dispenser or magazine (not shown) may be situated and, as desired, furnishes grids to the grid placement assembly. An orienter 31 may be provided at the other end of grid feed assembly 16 to approximately orient the grid members prior to seating in grid placement assembly 14.

The operation of the apparatus of Figure 4 in accordance with the present invention will be better understood by referring to Figures 5, 6, 7, 8 and 9, which show the disposition of 'a grid structure with respect to the insulated mounting support at various stages in the operation of the apparatus. Grid member 6 is allowed to fall in place as shown in Figure 5, in which the side rods or posts 8 are aligned in grooves or guide portions in the channel 25, as will be more clearly understood in connection with Figure 7, and with longitudinal erecting member 26 bearing against grid member 6. Operation of the air cylinder 27 causes the longitudinal erecting member 26 to pivot about pin 33. It should be noted in connection with Figure that grid member 6 is prevented from falling completely out of the channels 19 and 25 by being abutted against the opposed surface of channel 19, and by the position of the lower corner of erector 26 which swings in and thus constricts the passage through which the grid might otherwise fall. Operation of the air cylinder causes the longitudinal erecting member to become axially aligned with respect to the cathode 2 and thereby position the grid member 6 in axial alignment with the cathode. The erecting member 26 is so arranged that it snugly and accurately holds the grid member in the main channel 19. The grid placement assembly 14 is lowered by actuation of air cylinder 17 to bring the grid member 6 into position for placement on the insulating mounting plate 1. In Figure 7, which is a section of Figure 6 taken along section line 6-6, is shown the manner in which the grid member, shown for purposes of illustration as elliptical in cross section, is azimuthally aligned and secured in by corner portions 34 and 35 of channel 19.

In Figure 8 is shown the next stop in the operation of the apparatus. The ram or plunger member 20 is then moved into position by an actuation of air cylinder 21 to press against the ends of the grid member 6 remote from the mount 1 and secures the grid member on to the mount with the rods being secured in holes in the mount. The ram member 20 includes a hole 40 in the center thereof to clear the projection of the cathode 2 beyond the grid rods 7 of the grid member 6. The ram member also may be of a step form in the event that the side rods of the grid are of different length.

In Figure 9 the next step in the operation of the machine is represented. The grid placement assembly 14 is retracted by actuation of the air cylinder 17 freeing main channel 19 of the grid placement assembly from contact with the grid member while the ram 20 is retained in position to hold the grid member 6 down, thereupon the ram member 20 is removed and the operation is completed.

It will be appreciated by those skilled in the art that the invention may be carried out in various ways and may take various forms and embodiments other than those illustrated embodiments heretofore described. It is to be understood that the scope of the invention is not limited by the details of the foregoing desscription but will be defined in the following claims.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. Apparatus for assembling in an apertured support plate an electron discharge electrode having a plurality of extending feet adapted to be received in the apertures of the support plate, said apparatus comprising a support plate receiving station, a guide member having a first channel portion in axial registry with said support plate receiving station and dimensioned to receive electrodes with a snug fit, a second channel dimensioned for free sliding movement of electrodes therethrough and intersecting said first channel and angularly aligned therewith, an erecting member having a movable portion in one position forming an extension of one wall of said first channel and adapted to snugly hold said electrode in said first channel and in the other position forming an extension of one wall of said second channel, means for aligning the feet of said electrode with predetermined positions in said support plate receiving station corresponding to the location of apertures of a support plate having a predetermined location in said receiving station, and a ram member axially movable in said first channel to discharge an electrode from said first channel into engagement with a mounting plate having said predetermined location in said receiving station and to secure the feet thereof in said apertures.

2. Apparatus for assembling in an apertured support plate an electron discharge electrode having a plurality of extending feet adapted to be received in the apertures of the support plate, said apparatus comprising a support plate receiving station, a movable guide member having a first channel portion in axial registry with said support plate receiving station and dimensioned to receive electrodes with a snug fit, a second channel dimensioned for free sliding movement of electrodes therethrough and opening into said, first channel and angularly aligned therewith, an erecting member having a portion movable between one position forming an extension of the wall of said first channel and adapted to snugly hold said electrode in said first channel and another position forming an extension of the wall of said second channel, each of said channels including a pair of grooves for aligning the feet of an electrode therein, means for reciprocating said guide member to and from a delivery position in which the discharge end of such first channel is adjacent to said support plate receiving station, and a ram member axially movable in said first channel to discharge an electrode from said first channel when said guide member is in said delivery position.

3. Apparatus for assembling in an apertured support plate an electron discharge electrode having a plurality of extending feet adapted to be received in the apertures of the support plate, said apparatus comprising a support plate receiving station, a guide member having a first channel portion in axial registry with said support plate receiving station and dimensioned to receive electrodes with a snug fit, a second channel dimensioned for free sliding movement of electrodes therethrough and opening into said first channel and angularly aligned therewith, an erecting member having a portion movable between one position forming an extension of a wall of said first channel and another position forming an extension of a wall of said second channel, each of said channels including portions for aligning the feet of an electrode therein, means for advancing said guide member to a delivery position adjacent to said support plate receiving station, a ram member axially movable in said first channel to discharge an electrode in said first channel into engagement with a mounting plate in said receiving station and to secure the feet thereof in said apertures, means for retracting said guide member from said delivery position, and additional means for maintaining said ram member in engagement with an electrode discharged thereby during at least the first portion of retracting movement of said guide member.

References Cited in the file of this patent UNITED STATES PATENTS 1,492,602 Leveridge et al May 6, 1924 FOREIGN PATENTS 144,356 Australia Nov. 30, 1951 

